/**************************************************************************/
/*  tone_mapper.h                                                         */
/**************************************************************************/
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/*                             GODOT ENGINE                               */
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
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#ifndef TONE_MAPPER_RD_H
#define TONE_MAPPER_RD_H

#include "servers/rendering/renderer_rd/pipeline_cache_rd.h"
#include "servers/rendering/renderer_rd/shaders/effects/tonemap.glsl.gen.h"
#include "servers/rendering/renderer_scene_render.h"

#include "servers/rendering_server.h"

namespace RendererRD {

class ToneMapper {
private:
	enum TonemapMode {
		TONEMAP_MODE_NORMAL,
		TONEMAP_MODE_BICUBIC_GLOW_FILTER,
		TONEMAP_MODE_1D_LUT,
		TONEMAP_MODE_BICUBIC_GLOW_FILTER_1D_LUT,
		TONEMAP_MODE_SUBPASS,
		TONEMAP_MODE_SUBPASS_1D_LUT,

		TONEMAP_MODE_NORMAL_MULTIVIEW,
		TONEMAP_MODE_BICUBIC_GLOW_FILTER_MULTIVIEW,
		TONEMAP_MODE_1D_LUT_MULTIVIEW,
		TONEMAP_MODE_BICUBIC_GLOW_FILTER_1D_LUT_MULTIVIEW,
		TONEMAP_MODE_SUBPASS_MULTIVIEW,
		TONEMAP_MODE_SUBPASS_1D_LUT_MULTIVIEW,

		TONEMAP_MODE_MAX
	};

	enum {
		TONEMAP_FLAG_USE_BCS = (1 << 0),
		TONEMAP_FLAG_USE_GLOW = (1 << 1),
		TONEMAP_FLAG_USE_AUTO_EXPOSURE = (1 << 2),
		TONEMAP_FLAG_USE_COLOR_CORRECTION = (1 << 3),
		TONEMAP_FLAG_USE_FXAA = (1 << 4),
		TONEMAP_FLAG_USE_DEBANDING = (1 << 5),
		TONEMAP_FLAG_CONVERT_TO_SRGB = (1 << 6),
	};

	struct TonemapPushConstant {
		float bcs[3]; // 12 - 12
		uint32_t flags; //  4 - 16

		float pixel_size[2]; //  8 - 24
		uint32_t tonemapper; //  4 - 28
		uint32_t pad; //  4 - 32

		uint32_t glow_texture_size[2]; //  8 - 40
		float glow_intensity; //  4 - 44
		float glow_map_strength; //  4 - 48

		uint32_t glow_mode; //  4 - 52
		float glow_levels[7]; // 28 - 80

		float exposure; //  4 - 84
		float white; //  4 - 88
		float auto_exposure_scale; //  4 - 92
		float luminance_multiplier; //  4 - 96
	};

	/* tonemap actually writes to a framebuffer, which is
	 * better to do using the raster pipeline rather than
	 * compute, as that framebuffer might be in different formats
	 */
	struct Tonemap {
		TonemapPushConstant push_constant;
		TonemapShaderRD shader;
		RID shader_version;
		PipelineCacheRD pipelines[TONEMAP_MODE_MAX];
	} tonemap;

public:
	ToneMapper();
	~ToneMapper();

	struct TonemapSettings {
		bool use_glow = false;
		enum GlowMode {
			GLOW_MODE_ADD,
			GLOW_MODE_SCREEN,
			GLOW_MODE_SOFTLIGHT,
			GLOW_MODE_REPLACE,
			GLOW_MODE_MIX
		};

		GlowMode glow_mode = GLOW_MODE_ADD;
		float glow_intensity = 1.0;
		float glow_map_strength = 0.0f;
		float glow_levels[7] = { 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 0.0 };
		Vector2i glow_texture_size;
		bool glow_use_bicubic_upscale = false;
		RID glow_texture;
		RID glow_map;

		RS::EnvironmentToneMapper tonemap_mode = RS::ENV_TONE_MAPPER_LINEAR;
		float exposure = 1.0;
		float white = 1.0;

		bool use_auto_exposure = false;
		float auto_exposure_scale = 0.5;
		RID exposure_texture;
		float luminance_multiplier = 1.0;

		bool use_bcs = false;
		float brightness = 1.0;
		float contrast = 1.0;
		float saturation = 1.0;

		bool use_color_correction = false;
		bool use_1d_color_correction = false;
		RID color_correction_texture;

		bool use_fxaa = false;
		bool use_debanding = false;
		Vector2i texture_size;
		uint32_t view_count = 1;

		bool convert_to_srgb = false;
	};

	void tonemapper(RID p_source_color, RID p_dst_framebuffer, const TonemapSettings &p_settings);
	void tonemapper(RD::DrawListID p_subpass_draw_list, RID p_source_color, RD::FramebufferFormatID p_dst_format_id, const TonemapSettings &p_settings);
};

} // namespace RendererRD

#endif // TONE_MAPPER_RD_H